Here's an example of how a war goes:
The resources were held as follows:
Germany - Rubber
Egypt - Oil
Me (Greeks) - Coal, Horses and Saltpeter.
I'd dominated the late medieval period due to the resources I'd held. I had a mutal protection pact with the small and weak Germans and was trading for both Rubber and Oil.
I led in tech development, but just as I was about to develop Tanks the Egyptians launched an unprovoked surprise attack. Germany sided with me cutting on Egypts Rubber supplies.
On land the early stages of the war went my way as Rubberless Egypt were forced to send Riflemen against my Infantry. I siezed two Egyptian cities. At Sea Egypt dominated, lacking oil I couldn't compete with their navy.
Germany then made peace and began selling Egypt Rubber as well. Through sheer weight of numbers I still dominated but the war essentially degenerated into a vast stalemate - Infantry vs Infantry. Meanwhile once weak Germany grew very rich and started building numerous industrial wonders.
Then Egypt developed the tank. Briefly the war swung in their favour, but fortanately my artillery destroyed the harbour in Alexandria cutting off their supply of oil. Stalemate ensued.
Just an example of how the changing technology and supplies of vital resources affect the game. It worked beautifully.
